This patent document relates to fluidic devices and techniques in connection with particle sorting in fluid, including cytometry devices and techniques and applications in chemical or biological testing and diagnostic measurements.
Flow cytometry (FC) devices and systems can be used to characterize and analyze particles in fluid, e.g., physical and biochemical properties of cells and biochemical molecules or molecule clusters based on their optical responses as they are interrogated by external light sources in a serial manner. Optical signals from such particles can be collected by an optical detector, such as a photomultiplier tube (PMT), and are analyzed or processed to extract information carried by the optical properties of the particles. The optical signals from the particles can be caused by one or more interactions between the input light and the particles such as forward scattering (FSC), side scattering (SSC), and fluorescence.
Particle sorting, and in particular cell sorting (including cell sorting at the single-cell level) has become an essential feature in the field of flow cytometry as researchers and clinicians become more interested in studying and purifying certain cells such as stem cells, circulating tumor cells, and rare bacteria species. Cell sorting can be achieved by various techniques. One example is applying vibrations to the jet flow from the nozzle to cause breakage of jet flow into droplets and subsequently using electrically charged plates to deflect cell-containing droplets into their respective collection tubes (droplets of no interest flow straight down to the waste tube without deflection).
Flow cytometry (FC) devices and systems can be implemented based on microfluidic technologies for research assays and diagnostics as well as for clinical applications. Microfluidic technologies range from simple microfluidic channels to complex microfludic devices that can mix fluids, pump fluids, perform digital logic, individually culture cells, determine optimal reaction conditions, and much more. Small-scale fluidic devices have low Reynolds numbers and can be used to achieve controlled laminar flow systems. Microfluidics further offer the advantages of small size for miniaturization and parallelization of devices. The compact size of microfludic devices opens the door to the potential of portable devices. Additionally, various fabrication processes for microfludic devices are suitable for mass production which can reduce the cost of such devices. Advances in microfludic devices can lead to low-cost lab-on-a-chip devices, useful tools to researchers, clinical laboratories, and point-of-care clinicians in remote and/or resource-poor settings.